An Improved Method of USM Processing on Color Image

Abstract

Unsharp masking (USM) is an image manipulation technique, the principle of which is exaggerating the lighter-darker contrast between the two sides of an edge in order to enhance the visual definition of the image. In this study, typical computer image sharpening methods and defects were studied and the sharpening principle of traditional electronic scanners was adopted to propose an improved method of USM processing, that is, regard the most significant level change in color channel as the source image of extracting so as to obtain the edge enhancement information. Thus greater edge contrast was gained when applied to all channels. Experiments on RGB and CMYK images were conducted both by conventional and enhanced methods in Matlab. The results suggest that the improved image sharpening method could enhance the contrast of the image profile and get higher image definition degree.